1. Technical Field
The present invention relates to a liquid crystal display (LCD) panel and, more particularly, to an LCD panel capable of preventing light leakage and texture generation.
2. Discussion of the Related Art
A liquid crystal display (LCD) device displays an image by controlling light transmittance of respective liquid crystal cells arranged in a matrix form on an LCD panel according to video signals. To obtain a wide-viewing angle, the LCD device may employ, for example, a patterned vertical alignment (PVA) mode, an in-plane switching (IPS) mode, or a plane-to-line switching (PLS) mode.
In the PVA mode, a plurality of slits is formed on common electrodes and pixel electrodes of upper and lower substrates, and liquid crystal molecules located between the substrates are driven symmetrically with respect to the slits by fringe electric fields generated by the slits, thus forming a multi-domain structure.
In the IPS mode, a liquid crystal is driven by a horizontal electric field generated between a pixel electrode and a common electrode arranged in parallel on a lower substrate. In the IPS mode, the electrodes are formed on one substrate so that liquid crystal molecules are rotated in the plane of the same substrate and, as a result, an optical axis of a liquid crystal layer is rotated relative to the substrate.
In the PLS mode, a common electrode and a pixel electrode are provided in each pixel area with an insulating layer interposed therebetween to form a fringe electric field thereby causing all liquid crystal molecules filled between upper and lower substrates to be operated in the respective pixel areas.
However, in the IPS and PLS modes, residual images are generated and light transmittance is lowered since the electric fields are generated by the electrodes formed on one substrate. Moreover, in the PVA mode, the aperture ratio is low.
As an alternative to IPS, PLS and PVA, a dual field switching (DFS) mode has been proposed. In the DFS mode, a liquid crystal is aligned horizontally or vertically to an electric field generated between electric patterns of upper and lower substrates. The DFS mode improves side visibility and light transmittance by using fringe electric fields generated between pixel and common electrodes patterned on upper and lower substrates.
However, in an LCD device employing the DFS mode, a step height is formed by a pixel electrode and a storage electrode, which results in light leakage. In addition, a black brightness is increased by the light leakage thereby causing the capacity of a storage capacitor to be decreased. Moreover, since it is difficult to control the liquid crystal arranged in a position where the pixel electrode and a drain electrode are connected, an undesirable texture is generated.
Accordingly, there exists a need for an LCD panel that is capable of preventing light leakage and texture generation.